The present invention relates to a tool for cleaning and restoring internal pipe threads or the like. The tool by reason of its novel features is of relatively simplified construction and is, therefore, inexpensive to manufacture and is highly effective for the purposes intended.
Pipe systems or the like usually include internally threaded connecting elements such as elbows, T-joints and the like which in some instances are rather expensive castings. The internal threads of these castings are usually formed by a turning operation utilizing specially designed and specially made thread taps which are somewhat expensive. Often times in handling the pipe connecting elements on a site, or in the packing and shipping of these elements, the threads are bruised or buggered with the result that the male pipe elements cannot be assembled thereto. In some instances, the connecting elements and pipe for a system are delivered to a site and are exposed to atmospheric conditions for a prolonged period causing rusting of the threads. In some instances, it has been found that the rust build up prevents assembly of the pipe to the connecting elements. This of course necessitates retapping the connecting elements or recutting the male pipe threads. In most instances, the tap for the threads can only be accommodated on special turning equipment and, thus, reworking these threads usually necessitates sending the casting back to the manufacturing source which is time consuming and expensive. In some instances, it may even be necessary to scrap the casting which of course is a costly loss.
The present invention also has useful application in cleaning or restoring threads of stationary or permanent pipe installations that are capped by a threaded closure cap, such as access pipes to underground storage tanks or the like. On occasion, the internal pipe threads for the cap become damaged and must be repaired on the site for obvious reasons.
It has also been found that in some instances the nominal thread size for the interengaging parts i.e., the internal threads of the connecting element and external pipe threads are not within the prescribed tolerance limits and consequently the parts cannot be assembled for this reason. This, of course, may necessitate retapping the connecting element. Another alternative is to rethread the male pipe member if these threads are oversized in relation to the female threads of the connecting element.
Accordingly, it is an object of the present invention to provide a new and useful tool for repairing and restoring damaged threads.
It is also an object of the invention to provide such a tool which is portable and can be used by an operator independently of any automatic power actuating equipment.
A further object of the invention is to provide a tool which accommodates various thread sizes, types and diameters.
Another object is to provide such a tool which is simple, inexpensive and accurate.